Tuesday, December 24, 2013

Shopping for a science geek or a budding genius doesn’t have to be difficult. Whether it’s a gift for the holidays, a birthday, graduation, or a reward for a job well done, here is a list of the top 10 gifts for science geeks to help you give the perfect gift for that special someone on your mind.

The Science Chef Cookbook contains instructions for 100 edible experiments and recipes that teach kids science basics such as how yeast makes dough rise and what makes popcorn pop. As much fun to learn as it is to eat!

A Static Electricity Eliminatoris a great gift for anyone who is constantly getting zapped due to static. The Eliminator is an especially great gift for computer techs who are constantly rebuilding or repairing computers.

Friday, December 20, 2013

Tuberculosis (TB) is caused by a bacteria called Mycobacterium tuberculosis. The bacteria typically attacks the lungs, but TB bacteria can attack any part of the body such as the kidneys, spine and even the brain.

Tuberculosis is spread through the air from one person to another from coughing, sneezing, speaking or singing. People nearby breathe in these bacteria and become infected. Not everyone infected with TB bacteria will become sick however. Tuberculosis bacteria can live in the human body without making a person sick for years.

Treatment of TB uses antibiotics to kill the bacteria. Effective treatment can be difficult due to the unusual structure and chemical composition of the mycobacterial cell wall. This cell wall hinders the entry of drugs and makes many antibiotics ineffective.

Wednesday, December 18, 2013

Why would a biologist prefer a phase contrast microscope over a standard brightfield microscope? Here are a few reasons why phase contrast microscopes are preferred by many biologists over a variety of other microscopes available to them.

Cheek cells - phase contrast

Cheek cells - brightfield

The images shown above are both of the exact same slide of human cheek cells. The image shown at left was captured with brightfield and the image at right was captured with phase contrast.

A phase contrast microscope allows viewing a clear (transparent) specimen - a living cell - without staining the specimen, which effectively kills it, thereby eliminating the time consuming process of staining the specimen. This is preferred by biologists since living cells can be studied during cell division.

Light passing through a clear specimen undergoes phase changes, brightening areas of the specimen that creates a contrast against the darker areas. This contrast of light and dark makes the specimen visible to the human eye. This is important to biologists because the light contrasts with various mechanisms of the specimen, such as the membrane, cilia and flagella, against a lighter/darker background, making them visible under the microscope. Of importance in molecular biology, the phase contrast microscope enables biologists working in such fields as cancer research and developmental biology to distinguish one type of cell from another.

Phase contrast microscopes are capable of 50x to 1000x magnification. Such magnification is important to biologists because it allows visibility of activities at the cellular level such as protein motility, autography, cell signaling, and metabolism thereby broadening our understanding of cells.

A phase contrast microscope can be used for brightfield, (often darkfield) and phase contrast. Whereas a brightfield microscope can typically only be used for brightfield work.

Differences between a phase contrast microscope and a brightfield microscope.

Monday, December 16, 2013

Bacillus is a rod-shaped bacterium. Bacilli are an extremely diverse group of bacteria that include both the causative agent of anthrax (Bacillus anthracis) as well as several species that synthesize important antibiotics. In addition to uses in the medical field, bacillus spores, due to their extreme tolerance to both heat and disinfectants, are used to test heat sterilization techniques and chemical disinfectants.

Bacilli are also used in the detergent manufacturing industry because of their ability to synthesize important enzymes.

Bacilli are rod-shaped. Each bacterium only creates one spore, which is resistant to heat, cold, radiation, desiccation (extreme dryness), and disinfectants. Baccilli are capable of living in a wide range of habitats, including many extreme habitats such as the desert and the arctic.

Bacilli can cause infections ranging from ear infections and meningitis to urinary tract infections. They mainly occur as secondary infections in immunodeficient or compromised hosts. The most well-known disease caused by bacilli is anthrax. Antrax dates back many years, as it is assumed that the fifth and sixth plagues recorded in the Bible were anthrax (the fifth attacking animals and the sixth attacking humans). Anthrax in recent time has been brought into the public eye by being used for bio-terrorism.

There are three ways humans can contract anthrax: (1) Cutaneous anthrax occurs when contact with spores from dust particles or through an abrasion. (2) Gastrointestinal anthrax is contracted by ingesting contaminated meat. (3) Pulmonary anthrax results after inhaling spores that are transported to the lymph nodes where they multiply.

Bacillus captured at 1000x magnification without use of immersion oil.

Friday, December 13, 2013

Have you ever wondered how the inner components of a digital camera or computer could be manufactured with extreme precision? Such precision requires the use of a measuring microscope.

Measuring microscopes are excellent tools used in research and development, tool making, and industrial manufacturing for precision measurements of 2D and 3D parts, angles, shapes, linear dimensions, screw threads, and diameter of objects, including holes that are too small for a measurement probe. Quality control and quality measurement are key steps in the manufacturing process and measuring microscopes are used extensively during this process. Measuring microscopes are also necessary for inspecting a variety of objects such as semiconductors, electronic and electrical components, precision components, resin moldings, and medical products, making it possible to measure specimens that are too soft for contact measurement.

Measuring microscopes provide high power magnification and because the reflected light is pumped in through the objective lenses, opaque objects can be viewed. Some measuring microscopes also offer transmitted light from beneath the stage. The stage contains working room for larger objects, and the digimatic indicators allow for making measurements.

Measuring microscopes can measure up to 1/2 of a micrometer. Larger measuring microscopes are suitable for the following applications:

Length measurement in Cartesian and polar coordinates.

Angle measurements of tools such as threading tools, punches, and guages.

Thread measurements such as profiling major and minor diameters, height of lead, thread angle, profile position with respect to the thread axis and the shape of the thread.

Comparison of centers with drawn patters and drawing of projected profiles.

Verification of surface finish.

Measurement of surface defects.

Measurements of hardness test indentations.

Known for its high magnification and suitability for shop use, measuring microscopes are well built for a variety of applications in the industrial market.

Wednesday, December 11, 2013

A mushroom is a fleshy, spore-bearing fruiting body of a fungus. The term mushroom describes a variety of gilled fungi, with or without stems. The gills are seen below in detail (blue).

Photo: Captured in Strouds Run State Park, Athens, Ohio USA by Dan Molter

The terms "mushroom" and "toadstool" go back centuries and were never precisely defined. Toadstool was often a term applied to poisonous mushrooms or to those that have the classic umbrella-like cap and stem form. In German folklore and old fairy tales, toads are often depicted sitting on toadstool mushrooms and catching flies.

Gifts for Younger Kids (Ages 3-5)

Younger kids are often very interested in science, but they can't yet quite wrap their head around cells and biological specimens that can not be seen by the naked eye. However, they do love to look at things they are already familiar with such as flowers, rocks, toys from around the house, a dollar bill, etc. The MW1-L1 microscope provides 20x magnification and needs no light, cord, or batteries for operation. The single eyepiece is perfect for young kids to look through (rather than some binocular microscopes where the eyepieces can be too far apart for young children).

Gifts for Elementary School Kids (Age 6-11)

Elementary school age kids find it fascinating to look at microscope slides or Protozoans swimming in pond water. It can be a bit tricky for kids of this age to prepare their own slides, so prepared slides are usually the best route when starting off with a high power microscope for Elementary school age students.

High School students will have biology classes and can integrate their microscope into school work. A digital microscope allows them to view live images on the computer and capture and save images. The included software can make measurements as well.

Gifts for Hobbyists

Recommendation: A stereo microscope with magnification somewhere between 10x-40x is best for viewing stamps, coins, collections, etc.

Hobby microscopes allow the user to look at small parts or collections. Model railroaders or model builders paint small pieces and glue together parts. Stamp and coin collectors will want to examine dates and defects. Needle-pointers want to view small stitches. All of these hobbyists will do best with magnification somewhere in the range of 10x-40x. A dual power microscope with 10x and 30x is less expensive than a zoom microscope.

Thursday, December 5, 2013

The Thyroid Gland is a butterfly-shaped gland that resides on the lower front of the neck, just below the Adam's apple. When the thyroid is a normal size it can't be felt in the human body. The thyroid is full of blood vessels and its main job is to secrete several hormones called Thyroid Hormones. These act throughout the body to influence metabolism, growth and development, and body temperature.

The thyroid gland covers the windpipe from three sides. The thyroid gland produces hormones T3 and T4, which help the body to produce and regulate adrenaline, ephinephrine, and dopamine (all of which are active in brain chemistry). Without a functional thyroid, the human body can not break down proteins or process carbohydrates and vitamins. Thyroid gland problems often lead to weight gain.

Image courtesy: WebMD

The Thyroid gland can not produce hormones on its own. It requires help from the Pituitary gland. The Pituitary gland produces a thyroid stimulating hormone.

The thyroid gland is one of the largest endocrine glands and gets its name from the Greek adjective for "shield shaped" because of its shape relative to the thyroid cartilage.

In the human thyroid gland image above the follicles are labeled with "X". These are the follicles that selectively absorb iodine from the blood for production of thyroid hormones. 25 percent of the body's iodine ions are in the thyroid gland.

The follicular epithelial cells are labeled "Y". The follicles mentioned above are surrounded by a single layer of thyroid epithelial cells which secrete T3 and T4 hormones. When they are not secreting hormones, the epithelial cells range in size from low columnar to cuboidal cells. They are much taller columnar cells when active.

The endothelial cells (very small) are labeled with "Z". These cells are scattered among follicular cells and are found in spaces between spherical follicles. Their primary role is to secrete calcitonin, which acts to reduce blood calcium.

The above image of a human thyroid gland was captured at 1000x magnification. A 100x oil immersion objective was used, however immersion oil was not used when capturing the image (hence the lack of crispness in the image). Whenever using a 100x oil immersion lens, the best microscopy images will always be obtained when using immersion oil.